Topic: Pyrotechnic explosion lost mic channel

[beatkilla]

I taped rush and there were 2 loud explosions,during one at that exact moment the left channel is cancelled out.There is no other problems with that channel during any of the rest of the recording.What woukd cause that? This was my gear...DPA4061s...9volt battery box with roll off...11db attenuator...sony m10.low sensitivity.manual levels inbetween 3 and 4 and limiter is off.i was 7 rows back and the pyro i felt it had to be 3 times louder than the music.Could this of damaged my mic ?

[Patrick]

Does it still not work?  Is there no mic output?  Weak mic output?  Noisy?

There is a slight chance that the sudden impulse of sound could have physically damaged your mic diaphragm, but it would usually sound noisy or distorted after this happens as opposed to cutting out completely. 

If the mic works now, I'd blame it on the capsule distorting/clipping hard when it couldn't reproduce the intense pressure from the explosion.

[beatkilla]

It works fine,it was just during the explosion that there was no sound.

[gmm6797]

In my experience, the battery box/pre-amp can not take the sudden pressure change and over loads.
I regularly record shows with lots of pyro and have this issue.  Some pre's I have used take it better than others.  There is nothing you can do about it, IMHO

[SmokinJoe]

I'm guessing that there was such a surge in pressure that the circuit overloaded.  Maybe the diaphragm even went smack against the backplate.

Sound waves are just changes in air pressure, and when a bomb goes off the thing that kills people is a big local increase in air pressure (and maybe shrapnel).

If it sounds OK afterward, than it's okay.  If you are listening closely and can't decide if sounds OK... then I would guess it IS okay.

[Church-Audio]

I taped rush and there were 2 loud explosions,during one at that exact moment the left channel is cancelled out.There is no other problems with that channel during any of the rest of the recording.What woukd cause that? This was my gear...DPA4061s...9volt battery box with roll off...11db attenuator...sony m10.low sensitivity.manual levels inbetween 3 and 4 and limiter is off.i was 7 rows back and the pyro i felt it had to be 3 times louder than the music.Could this of damaged my mic ?

The main problem is this your "11db attenuator" is doing nothing to protect you from overloads. Any mic will overload except for a select few Bruel and Kjear mics during an explosion. Rolling off bass or adding an attenuator in line does nothing to solve mic distortion except make the overload signal more quiet. The 4061 mics will handle major spl but it sounds like for a brief second they were overloaded. No big deal, nothing you can do about it. Unless your mic is right beside the explosion in the pressure wave there is no damage that will occur.